Water Plasma Bonding for Soft Silicones: Rapid and Robust Fabrication of Soft Devices

Integration of soft silicone materials through bonding is essential for the fabrication of soft robots and stretchable electronics. However, bonding of soft silicones is dependent on limited methods that compromise softness, structural integrity, and process simplicity. While plasma bonding is a fast and robust bonding method that overcomes these problems, it is limited to relatively rigid silicones, such as polydimethylsiloxane (PDMS). In this work, we propose a method for robust bonding of soft silicones through a simple and rapid process by introducing water to a plasma treatment. We found that water plasma bonding requires a short treatment time under 100 s to activate the surfaces and achieves interfacial toughness greater than 1,000 J m^–2 within 3 min of bonding. We demonstrate the potential of the proposed method through multiple applications in which the rapidness, robustness, and increased versatility in the choice of materials allow novel and efficient modes of fabricating soft devices.